Magnetic Effects & Magnetism

JEE Main level, numerical answer, medium

32 of 276

Question 32 of 276

A solenoid of length 0.5 m0.5 \mathrm{~m} has a radius of 1 cm1 \mathrm{~cm} and is made up of ' m\mathrm{m} ' number of turns. It carries a current of 5 A5 \mathrm{~A}. If the magnitude of the magnetic field inside the solenoid is 6.28×10−3 T6.28 \times 10^{-3} \mathrm{~T} then the value of mm is _____.

Show answer and solution

Answer: 500

μ0ni=Bn=\mu_0 n i=B \quad n= number of turns per unit length
μ0(mℓ)i=B\mu_0\left(\frac{\mathrm{m}}{\ell}\right) \mathrm{i}=\mathrm{B}
m=B.ℓμ0i=6.28×10−3×0.512.56×10−7×5 m=500\begin{aligned} & \mathrm{m}=\frac{B . \ell}{\mu_0 \mathrm{i}}=\frac{6.28 \times 10^{-3} \times 0.5}{12.56 \times 10^{-7} \times 5} \\ & \mathrm{~m}=500\end{aligned}

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.

More Physics practice

JEE Main Physics practice question on Magnetic Effects & Magnetism (Magnetic Field), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.